KR20130069559A - Electrostatic parallel plate actuators whose moving elements are driven only by electrostatic force and methods useful in conjunction therewith - Google Patents

Abstract

An actuator device is provided. An actuator device that generates a physical effect that conforms to at least one characteristic of a digital input signal whose at least one attribute is periodically sampled in accordance with the sampling clock includes at least one actuator device and a controller. Each actuator device includes an array of movable elements and at least one electrode, each movable element acting to be restricted to alternately move back and forth along each axis in response to an individual first electrostatic force acting, each movable element Wherein the at least one electrode is driven away from the stop position only by the first electrostatic force and the at least one electrode is operative to apply controlled temporal differences in time order to at least one individual movable element of the array of movable elements. 1 Generates electrostatic force selectively. The controller receives the digital input signal and operates to control at least one of the at least one electrode and the respective movable element to apply the potential difference of the order.

Description

ELECTROSTATIC PARALLEL PLATE ACTUATORS WHOSE MOVING ELEMENTS ARE DRIVEN ONLY BY ELECTROSTATIC FORCE AND METHODS USEFUL IN CONJUNCTION THEREWITH}

Reference to co-pending applications

Priority not claimed. The pending applications are as follows:

The present invention generally relates to actuators, and more particularly to speakers.

A wide variety of actuators and speakers are known. As indicated above, some of the published applications of Applicant's co-pending applications describe state-of-the-art actuators such as speakers.

As used herein, the term bearing refers to any device that enables constrained relative motion, such as bending motion between parts, such as connecting the movable element to the stationary element and defining the movement path and the stop position of the movable element. It is intended to include a device. Flexure bearings or flexures are bearings that allow bending motion. Flexure bearings may include a flexible portion connecting the other two parts and are typically simple, inexpensive, compact and low in friction. The flexure bearing is formed of a material that can bend repeatedly without breaking. The spring is intended to include, but is not limited to, a suitable elastic member, such as a spirally wound strip or wire that regains shape after compression, bending, or stretching. The addressing of the (i, j) th actuator element in the actuator element array refers to the application of a voltage between a particular row and a particular column of the actuator element array.

An array is referred to herein as an "active" array when the elements of the array include element drive circuits and herein referred to as a "passive" array when the elements of the array do not include element drive circuits.

The terms 'stopped position', 'stopped position' and 'stopped position' are generally used equally herein. The terms 'actuator element' and 'actuating element' are used generally equally herein.

State-of-the-art speaker arrays and their useful control algorithms are described by Malcom Hawksford in the following publication:

end. "Spatial Distribution Of Distortion And Spectrally Shaped Quantization Noise In Digital Micro-Array Loudspeakers", J. Audio Engl Soc., Vol. 55, No. 1/2, January / February 2007; And

I. Smart Digital Loudspeaker Arrays ", J. Audio Engl Soc., Vol. 51, No. 12, December 2003.

When the terms "upper" and "lower" are used, they are used in the specification or drawings for convenience only to indicate the position on both sides of the plane defined by the array of movable elements, such as the plane connecting the midpoints of the trajectory of the movable element. It should be recognized. In many applications, gravity can be negligibly well positioned so that the "top" position is equally well below or to the left and right of the "bottom" position.

The terms may be understood according to the definitions indicated in the prior art documents or according to the specification, or as described above.

In the ANMS MEMS jargon, dimples are defined as "small features or projections, typically raised squares on the surface of MEMS devices." Dimples are used, for example, in devices with high aspect ratios. Can be used as a mechanical stop to control down.

The contents of all publications and patent documents mentioned in the specification, and the publications and patent documents cited therein directly or indirectly, are incorporated herein by reference.

Any embodiment of the present invention may respond to alternating magnetic fields or acting electromagnetic forces and the electrostatic force acts without the involvement of electromagnetic forces, as opposed to the actuator element described in the applicant's co-pending applications having only a latch function. It is an object to provide a movable element that moves in response to a first electrostatic force.

The invention typically includes at least the following examples:

1. An electrostatic parallel plate actuator device in which at least one property produces a physical effect that conforms to at least one characteristic of a digital input signal that is periodically sampled.

At least one electrostatic parallel plate actuator device, each actuator device comprising an array of conductive movable elements defining a first surface and at least one flat plate electrode defining a second surface generally parallel to the first surface, Each movable element is operated to be restricted to move back and forth alternately along each axis in response to each first electrostatic force acting, each movable element having a stop position and driven away from the stop position only by the first electrostatic force, At least one electrostatic parallel plate actuator device, wherein said plate electrode is operable to apply controlled temporal ordered potential differences with at least one individual movable element of said array of movable elements to selectively generate said first electrostatic force; And

A corrector parallel comprising a controller that receives the digital input signal and accordingly operates to control at least one of the at least one electrode and the respective movable element to apply a potential difference in the sequence such that the physical effect exhibits the signal. Plate actuator device.

2. The method of embodiment 1, wherein the movement of at least one of the movable elements along each axis is further constrained by at least one mechanical limiter disposed along the axis of the respective movable element, the mechanical limiter being extreme A device defining a position and preventing the movable element from moving beyond the extreme position.

3. The method of embodiment 2, wherein at least one of the movable elements having reached one of the extreme positions latches at least one of the movable elements by selectively preventing the mechanical limiter from returning to its previous position away from the mechanical limiter. And at least one latch that is operative.

4. The apparatus of embodiment 3, wherein the latching operation of the movable element is affected by a second electrostatic force generated by the electrode, the second electrostatic force acting in the same direction as the first electrostatic force.

5. The apparatus of embodiment 2, wherein the mechanical limiter and the electrode are integrally formed.

6. The method of embodiment 2, further comprising at least one projecting dimple disposed on at least one surface of the movable element and the mechanical limiter to create a gap between the surfaces when the movable element is in the extreme position. Device.

7. The device of embodiment 2, wherein the first electrostatic force described in paragraph 1 is adjusted in such a way as to limit the range of movement of the movable element to a shorter range than defined by the mechanical limiter, respectively. .

8. The apparatus of embodiment 1, wherein the controller controls the at least one electrode at regular time intervals to define an actuation clock frequency.

9. The apparatus of embodiment 8, wherein the mechanical resonant frequency of the movable element is adjusted to the actuation clock frequency.

10. The apparatus of embodiment 8, wherein the mechanical resonant frequency of the movable element is less than one half of the actuation clock frequency.

11. The apparatus of embodiment 8, wherein at least one characteristic of the digital input signal is sampled periodically in accordance with a sampling clock, wherein the actuation clock frequency is an integer multiple of the sampling clock frequency.

12. The apparatus of embodiment 9, wherein the mechanical resonant frequency of the movable element is 1/2 / of the actuation clock frequency.

13. The apparatus of embodiment 4, wherein the first and second electrostatic forces have the same amplitude and polarity.

14. The apparatus of embodiment 4, wherein the first and second electrostatic forces differ in at least one of amplitude and polarity.

15. The device according to any one of items 1 to 14, wherein at least one electrode extends across two or more actuator elements and controls their movement.

16. An actuation method for generating a physical effect that conforms to at least one characteristic of a digital input signal in which at least one attribute is periodically sampled,

Providing at least one electrostatic parallel plate actuator device, each actuator device defining an array of conductive movable elements defining a first surface and at least one flat plate electrode defining a second surface generally parallel to the first surface Wherein each movable element is operated to be restricted to move back and forth alternately along each axis in response to the respective first electrostatic force acting, each movable element having a stop position and away from the stop position only by the first electrostatic force. At least one electrostatic parallel plate actuator, wherein the plate electrode is adapted to generate the first electrostatic force selectively by applying potential temporal differences controlled by at least one individual movable element of the array of movable elements. Providing a device; And

Receiving the digital input signal using a controller and controlling at least one of the at least one electrode and the respective movable element accordingly to apply the potential difference in the sequence such that the physical effect exhibits the signal. Way.

17. The apparatus of embodiment 1, wherein the at least one actuator device is further configured to:

A first plurality of electrical connections driven by the controller and arranged in a first geometric pattern, hereinafter referred to as "row";

At least another plurality of electrical connections also driven by the controller and arranged in at least one other geometric pattern, hereinafter referred to as “column”, that is different from the first geometric pattern; And

Including a plurality of device driving circuits,

The first and other geometric patterns are designed such that each region where one row and one column overlap one includes one movable element,

Each of the element driving circuits controls one of the movable elements and is electrically connected to at least one of the one row and the columns,

And allow the controller to control the electrostatic forces acting on each of the movable elements indirectly by driving the rows and columns, thereby determining the behavior of the element drive circuit.

18. An electrostatic parallel plate actuator device in which at least one property produces a physical effect that matches at least one characteristic of a digital input signal that is periodically sampled.

At least one actuator device, each actuator device comprising an array of movable elements defining a first side and at least one flat plate electrode defining a second side parallel to the first side, each movable element (a) alternately move back and forth along each axis in response to each acting first electrostatic force and (b) be restricted to selectively latch into at least one latch position, wherein the electrode is operated at least one of the array of movable elements. At least one actuator device operative to apply a controlled temporal order of potential differences with an individual movable element to selectively generate said first electrostatic force; And

And a controller that receives the digital input signal and, accordingly, controls the at least one of the at least one electrode and the individual movable element to apply the potential difference in the sequence.

19. An electrostatic parallel plate actuation method for generating a physical effect that conforms to at least one characteristic of a digital input signal in which at least one property is periodically sampled,

Providing at least one actuator device, each actuator device comprising an array of movable elements defining a first face and at least one flat plate electrode defining a second face parallel to the first face, each And the movable element of (a) acts limited to move alternately back and forth along each axis in response to the respective first electrostatic force acting and (b) selectively latch to at least one latch position, wherein the electrode is an array of the movable element Providing at least one actuator device operative to apply a controlled temporal order of potential differences to at least one individual movable element of the first electrostatic force; And

Receiving the digital input signal using a controller and controlling at least one of the at least one electrode and the respective movable element to apply the potential difference of the sequence.

20. In the first embodiment,

The array of movable elements comprises a first plurality of first groups of electrically interconnected movable elements arranged in a first geometric pattern,

The at least one electrode comprises at least one electrode array separated into at least a second plurality of second groups of electrically interconnected electrodes arranged in at least one second geometric pattern different from the first geometric pattern; ,

Each of the first and second plurality of groups is electrically connected to the controller, and the first and second geometric patterns each region in which one first group overlaps one second group is one movable element. And the controller controls an electrostatic force acting on each of the movable elements in the array to address each of the movable elements by applying a voltage between each one of the first groups and each one of the second groups. Device, characterized in that it operates.

For example, the first and second groups include rows and columns but the configuration of each group need not be straight; Groups, such as rows and columns, consist of right angles to each other or nonzero angles; The angle between the intersecting first and second groups does not need to be the same at each intersection between the first and second groups. The number of movable elements per row may or may not be the same for the first group, such as each row, and the second group, such as columns. Where each movable element comprises two electrodes per movable element, the two electrodes can be selectively arranged in different patterns, respectively.

21. The embodiment of embodiment 20, wherein the actuating device comprises a plurality of arrays, each array comprising rows and columns that are each not electrically connected to the rows and columns of other arrays within the actuating device. Device.

22. The embodiment of the twentieth embodiment, wherein the first group comprises a row and the second group comprises a column and the rows and columns extend across two or more actuator devices such that the row is located within two or more actuator devices. An apparatus comprising a movable element and said row comprising electrodes located within at least two actuator devices.

23. In the twentieth embodiment, in succession for each row in the array, the controller periodically connects only each row to a predetermined potential while (a) keeping other rows electrically floating (b). A device for addressing the selected movable element in said respective row.

In each of these exclusively linked and also referred to herein as “selected,” the row to which the movable element is addressed includes or moves all the movable elements in the selected row, any subset of the movable elements in the selected row, or a single movable element in the selected row. It may not contain any device at all. Multiple movable elements in an exclusively connected row may be addressed simultaneously or at different points in time while the row remains selected. Scanning can also be done with rows and columns reversed. The controller can “select” columns periodically and address the selected movable elements in the selected rows by connecting one column to a known potential while keeping the other columns electrically floated. Repeat.

24. The apparatus of embodiment 4, wherein the controller releases the at least one movable element from the latched state by electrically connecting the movable element to the electrode.

25. The apparatus of embodiment 1, wherein the controller periodically refreshes the charge on the capacitor formed by the movable element and the electrode.

26. The method of embodiment 1, wherein the controller applies a voltage between at least one of the electrodes and at least one of the movable elements for a predetermined charging time that ends while the movable element is still in motion. And an electrostatic force acting on at least one of the movable element by preventing charge from being transferred to and from the capacitor formed by the movable element and the at least one electrode.

27. The apparatus of embodiment 1, further comprising at least one position sensor for sensing the position of the at least one movable element along each axis.

28. The apparatus of embodiment 27, wherein the position sensor comprises a capacitive sensor to sense capacitance between the movable element and the electrode.

29. The apparatus of embodiment 26, further comprising at least one position sensor for sensing the position of the at least one movable element along each axis.

30. The apparatus of embodiment 27, wherein the controller detects a defect of each movable element using information provided by the position sensor.

31. The apparatus according to embodiment 27, wherein the position information provided by the position sensor is used to adjust the voltage applied between at least one movable element and at least one electrode.

32. The apparatus of embodiment 29, wherein the charging time for the movable element is adjusted using the position information provided by the position sensor.

33. The apparatus of embodiment 27, wherein the controller uses the position information provided by the position sensor when selecting a movable element to create the physical effect.

34. The method of embodiment 29, wherein the position sensor includes a capacitance sensor to sense capacitance between the movable element and the electrode, wherein the capacitance while at least one of the movable element and the electrode is electrically floating. The sensor includes a voltage sensor operative to sense a voltage between the movable element and the electrode.

35. The apparatus of embodiment 34, wherein the voltage sensor comprises an analog comparator.

36. The apparatus of embodiment 34, wherein the voltage sensor comprises an analog to digital converter.

37. The apparatus of embodiment 18, wherein the movable element is selectively latched in at least one latch position by the at least one electrode.

38. The apparatus of embodiment 18, wherein the movement of at least one of the movable elements is limited by at least one mechanical limiter disposed along the axis of the respective movable element.

39. The apparatus of embodiment 2, wherein the electrode comprises a mechanical limiter disposed along an axis of the respective movable element and the limiter operates to limit the movable element.

40. The apparatus of embodiment 1, wherein the movable element is selectively latched by a first latch and a second latch to latch at least one subset of the movable element at corresponding first and second latch positions.

41. The third embodiment, wherein each movable element has at least one extreme position defined by the at least one mechanical limiter along the axis and the at least one movable element is latched to the at least one extreme position. Device.

42. The third embodiment, wherein each movable element has at least one extreme position defined by the at least one mechanical limiter along the axis and the at least one movable element is less than the extreme position of the movable element. And latched along the axis.

43. The first embodiment,

The array of movable elements includes a first plurality of rows of movable elements extending along a first geometric dimension and electrically connected therebetween,

The electrode comprises an electrode array comprising a second plurality of columns of electrodes parallel to the array of movable elements and electrically connected between and not parallel to the rows of movable elements arranged along a second geometric dimension,

The controller generates a physical effect by changing the voltage difference between the jth column and the Ith row of the plurality of columns and generates the jth element of the Ith row of the plurality of rows to induce the movement of the I, jth movable element. And an apparatus operative to determine whether to indicate movement of the I, j-th element.

44. The apparatus of embodiment 43, wherein the voltage source is changed by applying a voltage between the jth column and the Ith row of the second plurality of columns using a voltage source.

45. The apparatus of embodiment 43, wherein the voltage difference is changed by shorting between the jth column and the Ith row of the second plurality of columns.

46. The apparatus of embodiment 43, wherein the row is perpendicular to the column.

47. The twentieth embodiment, wherein a voltage source is used to apply a voltage between the b th column and the a th row of the second plurality of columns, and after a predetermined time, at least one of the a th row and the b th column is Disconnect from the voltage source and subsequently apply a voltage between the d-th column and the c-th row of the second plurality of columns using the voltage source, and after a predetermined time, connect at least one of the c-th and d-th columns from the voltage source By releasing, thereby causing the controller to determine whether to direct movement of the a, bth movable element and c, dth movable element to produce a physical effect and induce movement of the movable element.

48. The device of embodiment 43, wherein at least one of an I th row and a j th column is disconnected from the voltage source after the voltage is applied for a predetermined time.

49. The apparatus of embodiment 48, wherein the time ends while the I, jth movable element is still moving.

When some of the movable elements move, this is done by connecting the rows and columns of the first movable element to the voltage source, waiting for a certain time, disconnecting the rows and columns of the first movable element and doing the same for the second movable element. Can be scanned in order. If there are 17 movable elements (for example) to be moved and three of them (for example) are in the same row and column (for example) 1, 2, 8, then this row is continuously in columns 1, 2, 8 as described above. Rather than concatenating the rows, they can be concatenated with all three of columns 1, 2, and 8 simultaneously. Only if all of the movable elements to be moved are in a single column, the single column can be connected to a plurality of rows with each of the movable elements.

50. The apparatus of embodiment 43, further comprising a position sensor for sensing the position of the I, j th element along the axis.

51. The apparatus of embodiment 50, wherein the position sensor comprises a capacitive sensor.

52. The eleventh embodiment, wherein at least one of the I-th row and the j-th column is disconnected from the voltage source after the voltage is applied for a predetermined time, the time being the I, j-th movable element is still moving. And the capacitive sensor measures a change over time in the voltage difference between the I, j th movable element and the I, j th electrode.

The I, j electrode includes moving the moving element toward or away from it.

53. The apparatus of embodiment 50, wherein the voltage of the voltage source is adjusted using the position information provided by the position sensor.

54. The apparatus of embodiment 50, wherein the duration of the time is adjusted using location information provided by the location sensor.

55. The apparatus of embodiment 50, wherein if the position sensor detects that the movable element has an abnormal movement pattern, the controller marks the movable element as a defect and the movable element is no longer used. An example of the abnormal movement pattern is when the movable element does not arrive at a predetermined position along the axis at all.

56. The method of embodiment 50, wherein when the position sensor detects a difference between movement patterns of different movable elements, the position sensor infers a difference in at least one operating characteristic of the movable element in selecting the movable element. A device which takes into account the differences in the operating characteristics. The operating characteristic may include, for example, the amount of pressure generated by the movement of the movable element in response to a given electrostatic force.

57. The apparatus of embodiment 38, wherein the mechanical limiter comprises at least one protruding dimple on at least one of the major face of the movable element and the major face of the electrode. Main = plane perpendicular to the axis.

58. The method of embodiment 43, wherein a voltage source is used to apply a voltage between the b th column of the second plurality of columns and the a and c th rows, and after a predetermined time (i) both the a and c th rows And (ii) disconnecting at least one of the b-th column from the voltage source, thereby instructing the movement of the at least a, b-th and c, b-th movable elements to produce a physical effect and induce movement of the movable element. A device operative to determine whether a controller is

59. The method of embodiment 43, wherein a voltage source is used to apply a voltage between each of the b and d columns of the second plurality of columns and a row, and (i) the b and d times after a predetermined time. By disconnecting both columns and (ii) at least one of the a-th row from the voltage source, thereby creating a physical effect and inducing movement of the movable element, A device operative to determine whether a controller indicates movement.

60. The apparatus of embodiment 1, wherein the physical effect comprises sound and the property comprises at least one of amplitude and frequency.

61. A method of manufacturing an electrostatic parallel plate actuator device for producing a physical effect that conforms to at least one characteristic of a digital input signal in which at least one attribute is periodically sampled.

Providing at least one electrostatic parallel plate actuator device and a controller,

Each actuator device includes an array of conductive movable elements defining a first side and at least one flat plate electrode defining a second side generally parallel to the first side, each movable element having a respective agent acting thereon. 1 is restricted to move back and forth alternately along each axis in response to an electrostatic force, wherein each movable element has a stop position and is driven away from the stop position only by the first electrostatic force, wherein the plate electrode is in the array of movable elements Selectively generate the first electrostatic force by operating to apply controlled time differences of potential differences with at least one individual movable element,

A controller is configured to receive the digital input signal and thereby control at least one of the at least one electrode and each movable element to apply a potential difference in the sequence such that the physical effect exhibits the signal. Method of manufacturing the device.

62. The method of embodiment 61 wherein providing the at least one electrostatic parallel plate actuator device is made using a MEMS process.

Any trademarks appearing in the text or drawings are owned by their respective owners and are shown herein only to illustrate or illustrate one example of an embodiment of the invention.

Certain embodiments of the invention are shown in the following figures.
1 is a simplified functional block diagram of an actuator device constructed and operated in accordance with any embodiments of the present invention.
2A, 2B and 2C are cross-sectional views of individual actuator elements in the apparatus of FIG. 1, constructed and operated in accordance with certain embodiments of the present invention. Figure 2a shows the movable element in a resting position where no voltage is applied between the movable element and the two electrodes. 2B shows the movable element latched in one extreme position. 2C shows the movable element latched in the other extreme position.
3A, 3B and 3C are cross-sectional views of each actuator element in the device of FIG. 1 constructed and operated in accordance with any of the embodiments of the present invention, wherein the actuator element is provided with two electrodes, each of which also acts as a mechanical limiter. 130 and 140 are disposed opposite each other and comprise one movable element 120 suspended by a bearing 150. The movable element is spaced apart from the electrodes by two spacers 180 and 190. 3A shows the movable element in a stationary position with no voltage applied between the movable element and the two electrodes. 3B shows the movable element latched in one extreme position. 3C shows the movable element latched in the other extreme position.
4A, 4B, and 4C are cross-sectional views of each actuator element in the apparatus of FIG. 1 constructed and operated in accordance with certain embodiments of the present invention, wherein the actuator element is one movable suspended by a bearing 150. Element 120, and two electrodes 130 and 140 disposed opposite each other, and dimples 210 and 220 protruding on the surface of each electrode. 4A shows the movable element in a stationary position with no voltage applied between the movable element and the two electrodes. 4B shows the movable element latched at one extreme position with dimples 210 on one electrode 130 forming a void 240 between the movable element 120 and the electrode 130. 4C shows the movable element latched at the other extreme position, with the dimples 220 on the other electrode 140 forming a void 250 between the movable element 120 and the electrode 140.
5 is a cross-sectional view of the actuator device, showing one individual movable element 120 suspended by a bearing 150, with a single electrode 300 also serving as a mechanical limiter. The movable element is spaced apart from the electrode 300 by a single spacer 310.
6 shows a simplified representation of an array of actuator elements 110 in which each actuator element comprises a movable element 120 and one electrode 300, the movable elements arranged in a row and the electrodes arranged in a column. Schematic diagram.
FIG. 7 shows the array of FIG. 6 with a voltage applied between row i 330 and column j 340 to control the [i, j] -th movable element 350.
FIG. 8 shows the actuator device of FIG. 6 with a voltage applied between row i 330 and some columns 360 to control some movable elements 370 in row i.
FIG. 9 illustrates the actuator device of FIG. 8 with i row 330 electrically connected to j column 340 to release the [i, j] th movable element 350. Previously latched movable elements that are not electrically connected to each electrode 380 still remain latched.
10 shows that each movable element has two electrodes, the movable elements 120 are arranged in a row and the upper electrodes 130 and the lower electrodes 140 are arranged in separate columns (410 and 420, respectively). Is a simplified schematic diagram of an actuator device.
FIG. 11 includes a movable element 120 having a single electrode 300, and a one-sided element drive circuit 500 electrically connected to one row 510 and one column 520 of the actuator element array. Is a simplified schematic diagram of a cross-sectional matrix array device.
12 shows a movable element 120 having two electrodes 130 and 140, and a two-sided element electrically connected to one row 510 and two columns 521 and 522 of the actuator element array. A simplified schematic diagram of an active double sided matrix array element including circuitry 530, where each column controls one of two electrodes.
13 is a simplified schematic diagram of an actuating device including a plurality of “sub-arrays” 601-604. Each sub-array typically includes an array of actuator elements that are controlled by one controller 50 although each actuator element has its own dedicated rows and columns.
FIG. 14 is a simplified schematic diagram of a “super-array” comprising a plurality of actuator arrays 611, 612, 613, and 614, each controlling p rows of all arrays in the first row of the super-array. In this way, one electrical connection is controlled and control is performed in such a way that one electrical connection in the controller controls each of the p rows of all the arrays in the second row of the super-array.
15A, 15B and 15C illustrate changes in the mutual capacitance between the movable element and the electrode, the change in the voltage between them, the amount of charge stored in the mutual capacitance, and thus the electrostatic force acting on the movable element in some embodiments of the present invention. Graphs are shown as a function of the separation distance between the movable element and the electrode.
16A and 16B are simplified schematic diagrams of cross-sectional actuator elements including any type of voltage sensors 710 and 720 for providing any information regarding the position of the movable element 120 relative to the electrode 300. .
17 is a simplified schematic diagram of a double-sided actuator element having element drive circuitry in an array in which electrodes are shared between actuator elements.
FIG. 18 is a simplified schematic diagram of an actuator array including a plurality of double-sided actuator elements described above with reference to FIG. 17.

1 is a simplified functional block diagram of an actuator device constructed and operated in accordance with any embodiments of the present invention. The apparatus of FIG. 1 is operative to produce a physical effect, at least one property of which matches at least one characteristic of a digital input signal that is periodically sampled according to a sampling clock. The apparatus comprises, for example, at least one actuator array 100 comprising a plurality of actuator elements shown in FIGS. 2A-5, and a controller 50 operable to receive a digital input signal and to control actuator elements within the actuator array. ). Each actuator element may comprise a movable element and associated bearings, an electrode and a spacer between the electrode and the movable element, and mechanical limiters and / or dimples and / or mechanical actuation for all of the movable element as shown and described herein. An element driving circuit may be optionally included.

2A, 2B and 2C are cross-sectional views of a double-sided actuator element constructed and operated in accordance with certain embodiments of the present invention. The actuator element comprises a movable element 120 which is mechanically connected to the stationary portion of the actuator element by a suitable bearing 150 means such as a flexure or a spring. The bearing 150 defines an axis 125 through which the movable element 120 can move, prevents the movable element 120 from moving in another direction, and defines a stop position of the movable element 120. The actuator element further includes two electrodes 130 and 140 disposed on opposite sides of the movable element 120. In accordance with the digital input signal, the controller 50 (not shown) of FIG. 1 can apply a voltage between the movable element and the two electrodes, thereby generating an electrostatic force that will direct the movable element away from its stop position and toward each electrode. Can be. The pair of mechanical limiters 160 and 170 generally restrict the movable element 120 from moving along the axis 125 in both directions. The movable element 120 is spaced apart from the limiters 160 and 170 by spacers 180 and 190.

2A shows the movable element 120 in a stationary position with no voltage applied between the movable element 120 and the two electrodes 130 and 140. 2B shows the movable element latched in one extreme position. 2C shows the movable element latched in the other extreme position.

3A, 3B and 3C are FIGS. 2A, except that the separately formed mechanical limiters 160 and 170 of FIGS. 2A-2C are omitted and the electrodes 130 and 140 also act as mechanical limiters, respectively. Fig. 2C is a cross sectional view of an actuator element similar to the actuator element of Fig. 2C. This embodiment requires a passivation, such as a native oxide film, present on the silicon surface exposed to the atmosphere to prevent electrical shorts between the movable element and the two electrodes. Alternatively, non-natural passivation films may be added in one of the manufacturing process steps. 3A shows the movable element in a stationary position with no voltage applied between the movable element and the two electrodes. 3B shows the movable element latched in one extreme position. 3C shows the movable element latched in the other extreme position.

A particular advantage of this embodiment is that the manufacturing process is usually simpler and more cost effective than the manufacturing process for the actuator elements according to FIGS. 2A-2C.

4A, 4B and 4C show FIGS. 3A through 4 except that dimples 210 and 220, respectively, facing the movable element 120 are formed on the surfaces of the electrodes 130 and 140, respectively. A cross-sectional view of an actuator element similar to the apparatus of FIG. 3C. As a result, when the movable element 120 is in one extreme position, the movable element does not come into contact with the entire opposite surface of the electrodes 130 or 140, but instead the dimples formed on the electrodes 130 or 140, respectively. Contact only with 210 or 220 to form a gap, such as void 240. Since the device of the present invention is usually operated in the atmosphere, the term “void” is used herein only as an example, but need not be the case and alternatively, for example, the device may be operated in any other suitable medium. It is understood that.

It is also understood that dimples may be formed on the surface of the movable element 120 instead of the electrodes 210 and 220.

A particular advantage of this embodiment is that the voids 240 and 250 can allow air to flow quickly into the space between the movable elements and the electrodes, and / or the dimples 210 and 220 are for example squeeze films Because it prevents very strong bonding due to squeeze film effects, it is usually easier to release the movable elements 120 from their extreme positions than, for example, the embodiment of FIGS. 3A-3C. This may also be true for the embodiment of FIGS. 2A-2C, but making dimples is usually easier and more cost effective than making a separate mechanical limiter layer. 4A shows the movable element in a stationary position with no voltage applied between the movable element and the two electrodes. 4B shows the movable element latched in one extreme position. 4C shows the movable element latched in the other extreme position.

5 is a cross-sectional view of a sectional actuator element constructed and operated in accordance with certain embodiments of the present invention. The actuator element is generally similar to the actuator element of FIG. 3A and is also shown in the rest position. However, as described above, in FIG. 3A, a pair of spacers corresponding to the pair of electrodes is provided, whereas, unlike FIG. 3A, one side includes only a single electrode 300 and a single spacer 310. Similarly, it is understood that the cross-sectional form of the actuator devices of FIGS. 2A-2C and 4A-4C may be provided. It is understood that the orientation of the devices shown and described herein with respect to the horizontal need not be as shown. Thus, for example, the apparatus of FIGS. 2A-2B may be arranged horizontally as shown, or may be arranged vertically, for example. In addition, the apparatus of FIG. 5 may be set to that side or, if desired, may be reversed so that the electrode layer 300 is above the movable element 120 rather than vice versa. According to some embodiments, gravity may be neglected because the force acting on the movable element by the bearing 150 and the electrostatic force generated by the electrode or electrodes are several times multiplier by 10 than gravity.

FIG. 6 is a simplified schematic diagram of an actuator array including a plurality of cross-sectional actuator elements 110 arranged in rows and columns, wherein the cross-sectional actuator elements each have only one electrode 300. It is done. As shown, the electrical connection between the actuator elements is typically such that the movable elements 120 are electrically connected, for example, along the columns of the array, and the electrodes 300 are electrically connected, for example, along the rows of the array. . Controller 50 (not shown) of FIG. 1 is generally operated in conjunction with an array such that a voltage can be applied between any selected row and column.

FIG. 7 shows the actuator device of FIG. 6 in which voltage is applied by a controller between three rows and three columns (not shown), and as shown, all other actuator elements remain in the rest position (3, 3) The movable element 120 of the actuator element results in movement towards the single electrode 300 of the actuator element 3, 3.

FIG. 8 shows the actuator device of FIG. 6 with voltage applied by a controller (not shown) between 3 rows and 2, 3, and (q-1) columns, and as shown, all other than 3 Actuator elements remain in the rest position, while (3,2), (3,3) and (3, q-1) actuator elements are associated with a corresponding single electrode 300, i.e. actuator elements (3,2). , (3,3) and (3, q-1) each move toward the single electrode.

FIG. 9 shows the actuator device of FIG. 8 after the third row is shorted to the third column. As shown, the actuator elements (3,2) and (3, q-1) are as shown in Fig. 8 because the circuits are open so that charge is retained on these two actuator elements. Remain in the previous position. However, the actuator elements 3 and 3 return to the stop position because the voltage between the electrode and the movable element and the electrostatic force acting on the movable element are now zero.

FIG. 10 is a simplified schematic diagram of an actuator array including a plurality of double-sided actuator elements 110 arranged in rows and columns, wherein each double-sided actuator element has a pair of electrodes 130 and 140. Characterized in having a. As shown, the electrical connection between the actuator elements is typically as follows. (a) the movable elements 120 are electrically connected along the rows of the array, for example; (b) the first set of electrodes 130 are electrically connected along, for example, the columns 410 of the first set of arrays; And (c) the second set of electrodes 140 is electrically connected along, for example, the columns 420 of the second set of arrays. Controller 50 (not shown) is generally operated in conjunction with the array such that a voltage can be applied between any selected row and column.

FIG. 11 shows a general view of the individual elements of the actuator elements 110 of FIG. 6, except that the single-sided element drive circuit 500 is electrically connected to the rows 510 and columns 520 of the array to which the individual single-sided actuator elements belong. As a simplified schematic diagram of a similar cross-sectional actuator element. It is understood that one, some, or all of the actuator elements of FIG. 11 may include element drive circuit 500 as shown, or groups of elements may share a single drive circuit. The element driving circuit 500 is a relatively high voltage, for example several tens of volts, under the control of low voltage signals transmitted from the controller to each element driving circuit in the array along the rows and columns, for example the electrode 300 and the movable element. It may have a level shift function to be applied between the 120. Such high voltages can be useful for driving actuator elements depending on the needs of the application.

A particular advantage of this embodiment is that the controller (not shown) can include a completely low voltage device that operates at voltages commonly used in digital circuitry, such as 3.3 V, making the controller 50 more cost effective. Can be. Alternatively or additionally, the device drive circuit 500 may have a memory function that allows for effective simultaneous control of more actuator elements than can be physically addressed simultaneously, even though the device may no longer be able to be addressed. This is because the actuator elements (i, j) can maintain positions other than their stop positions even when they are not addressed.

FIG. 12 is generally associated with the individual of the actuator elements of FIG. 10 except that the two-sided element drive circuit 530 is electrically connected to the rows 510 and columns 521 and 522 of the array to which the individual two-sided actuator elements belong. It is a simplified schematic diagram of a similar double-sided actuator element (actuator element with two electrodes). It is understood that one, some, or all of the double-sided actuator elements of FIG. 10 may include an element drive circuit 530 as shown, or that groups of elements may share a single drive circuit. The element driving circuit 530 controls the voltage applied between the movable element 120 and the two electrodes 130 and 140 and has any of the functions described above in connection with the element driving circuit 500 of FIG. Can be.

FIG. 13 is a simplified schematic diagram of the actuator device of FIG. 1, provided with a plurality of actuator arrays, such as arrays 601, 602, 603 and 604 of n = 4 movable elements, all by a single controller 50. Controlled. In particular, one electrical connection in the controller controls each of the p rows and each of the q columns of one array, and so on for each array, continuing for n arrays of p × q actuator elements. A total of n (p + q) electrical connections are provided to the controller. In the embodiment shown, n = 4, p = q = 9.

FIG. 14 is a simplified schematic diagram of the actuator device of FIG. 1, provided with a plurality of identical arrays, such as arrays 611, 612, 613 and 614 of movable elements where n = 4, all by a single controller 50. Controlled. However, in FIG. 14, in contrast to FIG. 13, the arrays themselves are arranged in one array, referred to herein as P × Q “super-arrays,” out of all the arrays in the first row of super-arrays. A super-array continues in such a way that one electrical connection in each of the p rows is controlled by the controller, and one electrical connection in the controller controls each of the p rows of all arrays in the second row of the super-array. One electrical connection in the controller controls each of the p rows of all the arrays in the last P row of the controller. Similarly, one electrical connection in the controller controls each of the q columns of all the arrays in the first column of the super-array, and each of the q columns of all the arrays in the second column of the super-array is one in the controller. Continuing in such a way that the electrical connection of the controller controls, one electrical connection in the controller controls each of the q columns of all the arrays in the last Q column of the super-array. In general, a total (P × p + Q × q) electrical connection is provided for the P × Q “super-array” of p × q actuator arrays. In the embodiment shown, n = 4, p = q = 9; P = Q = 2.

FIG. 15A is a graph showing the mutual capacitance between electrodes of a movable element and an actuator element as those described above with respect to FIGS. 1-14 as a function of the separation distance therebetween. Particular values of the graphs are graphically depicted for an exemplary circular actuator element both having a movable element and an electrode having a diameter of 300 μm and modeled as a parallel plate capacitor whose dielectric is air.

FIG. 15B shows the voltage between the parallel plate capacitors of FIG. 15A and the charge stored in the capacitor as a function of separation distance. In the example shown, initially, at a separation distance of 3 μm, the controller applies a voltage of 50 V between the capacitors. The separation distance then decreases over time. After the separation distance reaches 1 μm, the controller opens an electrical connection to the electrode or movable element so that charge can no longer enter or exit the capacitor. From this point in time, the voltage between the movable element and the electrode decreases as the separation distance decreases.

FIG. 15C shows the electrostatic force acting on the movable element of FIGS. 15A and 15B as a function of the distance from the electrode. Initially, with a constant voltage applied between the electrode and the movable element, the electrostatic force increases as the separation distance decreases. However, after the controller opens the electrical connection, the electrostatic force remains constant as the separation distance further decreases.

16A and 16B are simplified schematic diagrams of cross-sectional actuator elements including a voltage sensor. An electrode drive circuit 700 is provided that may be part of the controller shown in FIG. 1 or may be the same as the cross-sectional device drive circuit 500 of FIG. 11. The electrode drive circuit 700 initially charges the capacitor formed by the electrode 300 and the movable element 120 to a non-zero voltage, and then disconnects at least one of the movable element or the electrode to allow charge into or out of the capacitor. Do not move at all. The movable element 120 then moves randomly toward or away from the electrode 300, causing the voltage on the capacitor to decrease or increase, respectively. The voltage sensor can sense this change in voltage while providing information about the position of the movable element 120.

In FIG. 16A, the voltage sensor is an analog comparator 170 having a sense output comprising a binary signal indicating whether the voltage between the electrode and the movable element is above or below the reference voltage.

In FIG. 16B, the voltage sensor is an analog-to-digital converter 720 having a sense output that includes a multilevel instead of binary, typically a numerical representation of the voltage between the electrode and the movable element.

FIG. 17 is a simplified schematic diagram of a double-sided actuator element with element drive circuit 532 in an array in which electrodes are shared between actuator elements. The first electrode 130 is connected to the first potential 533, the second electrode 140 is connected to the second potential 534, and the element driving circuit 532 is electrically connected to the movable element 120. Has only one output.

According to certain embodiments, the voltage between the top electrode and the bottom electrode in a normal operating state is substantially constant, or varies at a rate several orders of magnitude lower than the actuation clock frequency. The element drive circuit 532 includes, for example, a digital CMOS push-pull output step that can couple the movable element 120 to one of the first potential 533 and the second potential 534. When the movable element 120 is connected to the first potential 533, the voltage between the movable element and the first electrode 130 is zero and the voltage between the movable element 120 and the second electrode 140 is not zero, The electrostatic force that pulls the movable element 120 toward the second electrode 140 is generated. Likewise, when the movable element 120 is connected to the second potential 534, the voltage between the movable element and the second electrode 140 is zero and the voltage between the movable element 120 and the first electrode 130 is not zero. As a result, the electrostatic force that pulls the movable element 120 toward the first electrode 130 is generated.

Cross-sectional actuator elements such as those shown in FIG. 5 or 11 may alternatively be composed of electrodes shared between the actuator elements. The device driving circuit 532 may be implemented using techniques such as but not limited to bipolar transistors, in addition to CMOS. The output of the element drive circuit can vary continuously, rather than being limited to two levels as described above. The output of the device drive circuit may have a high-impedance state (known in the art as "3-state" or "high-Z"), and as described above in connection with FIG. 15B, with the movable element 120. No charge is transferred into or out of the pair of parallel plate capacitors formed by the two electrodes.

FIG. 18 is a simplified schematic diagram of an actuator array including a plurality of the above-described double-sided actuator elements in connection with FIG. 17. According to some embodiments, the first electrode 130 of each actuator element is electrically connected to the first electrode of all other actuator elements, and the first potential 533, and likewise, the second electrode of each actuator element. 140 is electrically connected to the second electrode of all other actuator elements, and to the second potential 534.

A particular advantage over the embodiment of FIG. 18 is that actuator element arrays such as the actuator arrays shown in FIGS. 6 and 10 or those shown in FIGS. 11 and 12 include electrical isolation between the electrodes of each actuator element. On the other hand, there is no need for electrical insulation between any first electrodes or any second electrodes. Thus, all of the electrodes of FIG. 18 can be disposed on both sides of the movable elements 120 and implemented as two continuous layers of electrically conductive material, such as doped silicon or aluminum, and these layers are electrically insulated. There is no need to divide into. This allows for easier and more cost effective manufacturing processes.

A control algorithm suitable for implementing the controllers shown and described herein, such as the controller 50 of FIG. 1, is now described. In general, a controller controls each movable element position in the actuator device as a function of a digital input signal sampled in accordance with a sampling clock. According to one embodiment of the invention, the range of the digital input signal can be such that the number of values the signal can assume is equal to the number of actuator elements in the device and the sampling clock can have the same frequency as the actuation clock. . In this case, the controller can implement an algorithm that determines the number of movable elements where each data word of the digital input signal is at an arbitrary location.

For example, in a device using single-sided actuator elements, the number of movable elements latched in the device is always equal to the number represented by the most recent (most recently received) data word of the digital input signal received by the controller. Individual movable elements can be latched or released. Alternatively, the algorithm may be such that the number of unlatched movable elements is the same as the most recently received data word. In embodiments of the double-sided actuator elements, the algorithm may be such that the number of movable elements latched to the first extreme position, or alternatively the number of movable elements latched to the second extreme position, is equal to the most recently received data word. Alternatively, the controller can implement an algorithm that determines a number of actuator elements where each data word of the digital input signal is to be moved (eg, raised or lowered) along each axis.

In order to reproduce the digital input signal more accurately, other control algorithms can also take into account the impulse response of the actuator elements. The control algorithm may include additional signal processing functions, such as but not limited to volume and tone control, as described in Applicant Serial No. WO2007 / 135679, filed by applicants entitled “Volume And Tone Control In Direct Digital Speakers”. It may be. In general, the number of values assumed by the digital input signal may be different from the number of actuator elements in the device, and thus the controller may include a scaling function to match the digital input signal to the number of possible actuator elements. Similarly, the sampling clock may be different from the actuation clock, so the controller may include resampling, sampling rate conversion, interpolation, or decimation functions to set the sampling clock to the actuation clock.

When the number of actuator elements in the device is less than the number of values that the digital input signal can take and the actuation clock frequency is higher than the sampling clock frequency, oversampling, noise shaping to minimize the quantization noise effect and increase the effective resolution of the actuator device Known techniques such as, and sigma-delta modulation can be used. In this regard, reference is made to the patent by M. Hawksford, referenced above.

Depending on the application, various different criteria can be used to select which specific drive elements are latched or released at a given time. For example, in order to generate the desired directivity pattern described in the Applicant's pending application serial number WO2007 / 135678 (“Direct digital speaker apparatus having a desired directivity pattern”), the controller occupies certain positions in the actuator device. Drive elements can be selected. Alternatively, to minimize the effects of device mismatch (primary terminology), the controller can select movable elements in a pseudo-random manner. Another option is for the controller to select moving elements in a way that simplifies the control algorithm. These or any other selection criteria may be combined.

The controller may include an industry standard interface for receiving the digital input signal, such as an I2S, AC'97, HAD, or SLIM bus interface (all of which are known terms and may be trademarks).

Movable elements and electrodes or electrodes are typically made of an electrically conductive material, such as doped monocrystalline silicon, doped polycrystalline silicon, or aluminum, or include at least an electrically conductive layer. The space layers between the movable elements and the electrodes are usually made of an electrically insulating material such as silicon dioxide or at least include an electrically insulating layer. In the absence of electrostatic forces, the bearings are usually elastically deformable without plastic deformation, such as single crystal silicon, so that the bearings do not undergo any permanent deformation and the movable elements always return to the exact same stop position when no electrostatic force is applied. It is made of a material such as polycrystalline silicon, or aluminum.

Cost-effective mass production of the actuator devices described herein can be achieved, for example, as follows. In existing microfabrication plants (known in the art as "fabs"), wafers of industry standard dimensions, such as 6 inch or 8 inch diameter, such as silicon or aluminum wafers or silicon on insulator (SOI) wafers, It can be used as a substrate for manufacturing an actuator device. Depending on the desired actuator device size and wafer size, one wafer may have sufficient surface area to fabricate tens, hundreds, or more actuator devices. Alternatively, if a large actuator device is desired, the actuator device can be designed to fill the entire surface of one wafer. Nevertheless, a larger actuator device can be constructed by combining several large actuator device arrays into one device, each as one fills the entire wafer, as described with respect to FIGS. 13 and 14. have. Wafers can be processed using existing fabric equipment designed for this batch size, for example in an industry standard batch size that processes 25 wafers at a time.

The actuator device manufacturing process typically includes continuous process steps, resulting in fully equipped actuator devices. Each process step follows techniques known in the semiconductor or MEMS industry, and suitable equipment for it is not limited, but commercially available such as photolithography, etching, thermal oxidation, chemical vapor deposition, trench isolation, ion implantation, and diffusion. have. Typically each process step generates any feature for all actuator elements of all actuator devices on the same wafer at the same time in one step. For example, all bearings of all actuator elements on a wafer may be formed in one etching process, all electrodes on the wafer may be doped in one ion implantation or diffusion process to improve electrical conductivity, and / Alternatively, all electrodes or all movable elements on the wafer can be electrically separated from one another in one trench isolation step.

Cost-effective mass production of the controller described herein can be achieved by implementing the controller in an application specific semiconductor (ASIC-terminology), for example, using industry standard techniques such as CMOS. Alternatively or in addition, existing, standard electronic components can be used to implement some or all of the components of the controller. Such electronic components include, but are not limited to, integrated circuits such as FPGAs, CPLDs, DSPs, or microprocessors (all of which are known); Individual electronic components such as MOSFETs, bipolar transistors, diodes, or passives; Or any combination of integrated circuits and individual electronic components, including but not limited to. Any parts of the controller may be implemented in software rather than in electronic circuitry embedded in hardware. These software components can be executed by any suitable engine, such as, but not limited to, a microprocessor, microcontroller or DSP, and are not limited to native machine code, but not limited to higher level programming languages such as C, C ++, or Perl. Although not exhaustive, it may be written in a modeling language such as MATLAB or any suitable programming language, including but not limited to any hardware description language such as Verilog or VHDL.

Forming the entire apparatus, including the controller and the actuating device, may comprise fabricating one die on the same wafer. Depending on the preferred size of the actuator device, the size of the controller and the wafer size, one wafer may provide a large number of these devices or just one such devices. Alternatively, the parts of the controller may be made of parts of the same die as the associated actuator device, with other parts made of separate integrated circuits, made from existing, standard electronic parts, or implemented in software, Or combinations thereof. When some or all parts of the controller are manufactured in an integrated circuit separately from the actuator device, the two separate manufacturing processes of the controller and the actuator device differ in process flow, process shape, number of process steps, number of masks or any other characteristic, respectively. can do. This allows each manufacturing process to be optimized separately, for example to achieve the lowest overall cost, minimum size, highest yield (main term), or any other desired property.

In alternative implementations, terms such as “mandatory”, “essential”, “necessary” and “must” are used for clarity because the same elements may be defined as non-mandatory and unnecessary, or even completely eliminated. It is understood that the selection of the implementation is made within the context of the specific implementation or application described herein and is not intended to be limiting.

It is understood that any of the functions described herein, such as moving element control functions, may be implemented in software if desired.

Features of the invention described in the context of separate embodiments may be provided in combination in one embodiment. Conversely, features of the invention, including method steps described for brevity or in any order in one embodiment context, may be provided separately or in any suitable subcombination or in a different order. As used herein, “for example” is used in the sense of specific examples, which is not intended to be limiting.

In the specification and drawings described and shown herein, the functions described or illustrated in the system and its subunits may be provided as a method and its steps, and the functions described or illustrated as the method and its sub-units may include the system and its subunits. It is understood that it may be provided. The scale used to illustrate the various elements in the figures is merely illustrative and / or appropriate for clarity of presentation and is not intended to be limiting.

Claims (62)

An electrostatic parallel plate actuator device in which at least one property produces a physical effect that matches at least one characteristic of a digital input signal that is periodically sampled,
At least one electrostatic parallel plate actuator device, each actuator device comprising an array of conductive movable elements defining a first surface and at least one flat plate electrode defining a second surface generally parallel to the first surface, Each movable element is operated to be restricted to move back and forth alternately along each axis in response to each first electrostatic force acting, each movable element having a stop position and driven away from the stop position only by the first electrostatic force, At least one electrostatic parallel plate actuator device, wherein said plate electrode is operable to apply controlled temporal ordered potential differences with at least one individual movable element of said array of movable elements to selectively generate said first electrostatic force; And
A corrector parallel comprising a controller that receives the digital input signal and accordingly operates to control at least one of the at least one electrode and the respective movable element to apply a potential difference in the sequence such that the physical effect exhibits the signal. Plate actuator device. The method of claim 1,
Movement of at least one of the movable elements along each axis is further constrained by at least one mechanical limiter disposed along the axis of the respective movable element, the mechanical limiter defining an extreme position and positioning the movable element at the extreme Device that prevents movement out of position. The method of claim 2,
And at least one latch operative to latch at least one of the movable elements by selectively preventing at least one of the movable elements reaching one of the extreme positions from returning to a previous position away from the mechanical limiter. Device. The method of claim 3,
The latch action of the movable element is affected by a second electrostatic force generated by the electrode, the second electrostatic force acting in the same direction as the first electrostatic force. The method of claim 2,
The mechanical limiter and the electrode are integrally formed. The method of claim 2,
And at least one protruding dimple disposed on at least one surface of the movable element and the mechanical limiter to create a gap between the surfaces when the movable element is in the extreme position. The method of claim 2,
The device of claim 1, wherein the first electrostatic force is adjusted in a manner that limits the range of movement of the movable element to a shorter range than defined by the mechanical limiter, respectively. The method of claim 1,
And the controller controls the at least one electrode at regular time intervals to define an actuation clock frequency. 9. The method of claim 8,
And wherein the mechanical resonant frequency of the movable element is adjusted to the actuation clock frequency. 9. The method of claim 8,
And the mechanical resonant frequency of the movable element is less than one half of the actuation clock frequency. 9. The method of claim 8,
And at least one characteristic of the digital input signal is periodically sampled in accordance with a sampling clock, wherein the actuation clock frequency is an integer multiple of the sampling clock frequency. 10. The method of claim 9,
And the mechanical resonant frequency of the movable element is one half of the actuation clock frequency. 5. The method of claim 4,
Wherein the first and second electrostatic forces have the same amplitude and polarity. 5. The method of claim 4,
Wherein the first and second electrostatic forces differ in at least one of amplitude and polarity. The method according to any one of claims 1 to 14,
At least one electrode extends across two or more actuator elements and controls movement thereof. An actuation method for generating a physical effect that conforms to at least one characteristic of a digital input signal in which at least one attribute is periodically sampled,
Providing at least one electrostatic parallel plate actuator device, each actuator device defining an array of conductive movable elements defining a first surface and at least one flat plate electrode defining a second surface generally parallel to the first surface Wherein each movable element is operated to be restricted to move back and forth alternately along each axis in response to the respective first electrostatic force acting, each movable element having a stop position and away from the stop position only by the first electrostatic force. At least one electrostatic parallel plate actuator, wherein the plate electrode is adapted to generate the first electrostatic force selectively by applying potential temporal differences controlled by at least one individual movable element of the array of movable elements. Providing a device; And
Receiving the digital input signal using a controller and controlling at least one of the at least one electrode and the respective movable element accordingly to apply the potential difference in the sequence such that the physical effect exhibits the signal. Way. The method of claim 1,
The at least one actuator device also includes:
A first plurality of electrical connections driven by the controller and arranged in a first geometric pattern, hereinafter referred to as "row";
At least another plurality of electrical connections also driven by the controller and arranged in at least one other geometric pattern, hereinafter referred to as “column”, that is different from the first geometric pattern; And
Including a plurality of device driving circuits,
The first and other geometric patterns are designed such that each region where one row and one column overlap one includes one movable element,
Each of the element driving circuits controls one of the movable elements and is electrically connected to at least one of the one row and the columns,
And allow the controller to control the electrostatic forces acting on each of the movable elements indirectly by driving the rows and columns, thereby determining the behavior of the element drive circuit. An electrostatic parallel plate actuator device in which at least one property produces a physical effect that matches at least one characteristic of a digital input signal that is periodically sampled,
At least one actuator device, each actuator device comprising an array of movable elements defining a first side and at least one flat plate electrode defining a second side parallel to the first side, each movable element (a) alternately move back and forth along each axis in response to each acting first electrostatic force and (b) be restricted to selectively latch into at least one latch position, wherein the electrode is operated at least one of the array of movable elements. At least one actuator device operative to apply a controlled temporal order of potential differences with an individual movable element to selectively generate said first electrostatic force; And
And a controller that receives the digital input signal and operates to control at least one of the at least one electrode and the respective movable element to apply the potential difference in the sequence. An electrostatic parallel plate actuation method for generating a physical effect that conforms to at least one characteristic of a digital input signal in which at least one attribute is periodically sampled,
Providing at least one actuator device, each actuator device comprising an array of movable elements defining a first face and at least one flat plate electrode defining a second face parallel to the first face, each And the movable element of (a) acts limited to move alternately back and forth along each axis in response to the respective first electrostatic force acting and (b) selectively latch to at least one latch position, wherein the electrode is an array of the movable element Providing at least one actuator device operative to apply a controlled temporal order of potential differences to at least one individual movable element of the first electrostatic force; And
Receiving the digital input signal using a controller and controlling at least one of the at least one electrode and the respective movable element to apply the potential difference of the sequence. The method of claim 1,
The array of movable elements comprises a first plurality of first groups of electrically interconnected movable elements arranged in a first geometric pattern,
The at least one electrode comprises at least one electrode array separated into at least a second plurality of second groups of electrically interconnected electrodes arranged in at least one second geometric pattern different from the first geometric pattern; ,
Each of the first and second plurality of groups is electrically connected to the controller, and the first and second geometric patterns each region in which one first group overlaps one second group is one movable element. And the controller controls an electrostatic force acting on each of the movable elements in the array to address each of the movable elements by applying a voltage between each one of the first groups and each one of the second groups. Device, characterized in that it operates. 21. The method of claim 20,
And the actuating device comprises a plurality of arrays, each array having rows and columns that are each not electrically connected to the rows and columns of other arrays within the actuating device. 21. The method of claim 20,
The first group comprises a row and the second group comprises a column and the rows and columns extend across two or more actuator devices such that the row comprises movable elements located within two or more actuator devices and the column comprises two or more And an electrode located within the actuator device. 21. The method of claim 20,
Continuously for each row in the array, the controller periodically connects only each row to a predetermined potential while (a) keeping all other rows electrically floating, and (b) the movable elements selected in each row. Device for addressing. 5. The method of claim 4,
And the controller releases the at least one movable element from the latched state by electrically connecting the movable element to the electrode. The method of claim 1,
And a controller periodically refreshes the charge on the capacitor formed by the movable element and the electrode. The method of claim 1,
The controller applies a voltage between at least one of the electrodes and at least one of the movable elements for a predetermined charging time which is terminated while the movable element is still in motion and then applies the voltage to the at least one movable element and the at least one electrode. And an electrostatic force acting on at least one of the movable elements by preventing charge from being transferred to and from the capacitor formed by the capacitor. The method of claim 1,
And at least one position sensor for sensing the position of the at least one movable element along each axis. 28. The method of claim 27,
The position sensor includes a capacitive sensor for sensing the capacitance between the movable element and the electrode. The method of claim 26,
And at least one position sensor for sensing the position of at least one movable element along each axis. 28. The method of claim 27,
And the controller detects a defect of each movable element using the information provided by the position sensor. 28. The method of claim 27,
And adjust the voltage applied between the at least one movable element and the at least one electrode using the position information provided by the position sensor. 30. The method of claim 29,
And adjusting the charging time for the movable element by using the position information provided by the position sensor. 28. The method of claim 27,
And the controller uses the position information provided by the position sensor when selecting a movable element to create the physical effect. 30. The method of claim 29,
The position sensor includes a capacitive sensor to sense capacitance between the movable element and the electrode, while the capacitive sensor is configured to detect a voltage between the movable element and the electrode while at least one of the movable element and the electrode is electrically floating. A device comprising a voltage sensor operative to sense. 35. The method of claim 34,
The voltage sensor comprises an analog comparator. 35. The method of claim 34,
The voltage sensor comprises an analog to digital converter. 19. The method of claim 18,
And the movable element is selectively latched in at least one latch position by the at least one electrode. 19. The method of claim 18,
Movement of at least one of the movable elements is limited by at least one mechanical limiter disposed along an axis of the respective movable element. The method of claim 2,
The electrode includes a mechanical limiter disposed along the axis of each movable element, the limiter operative to limit the movable element. The method of claim 1,
And wherein the movable element is selectively latched by a first latch and a second latch to selectively latch at least one subset of the movable element at corresponding first and second latch positions. The method of claim 3,
Wherein each movable element has at least one extreme position defined by the at least one mechanical limiter along the axis and at least one movable element is latched to the at least one extreme position. The method of claim 3,
Wherein each movable element has at least one extreme position defined by the at least one mechanical limiter along the axis and the at least one movable element is latched along the axis to a position less than the extreme position of the movable element. The method of claim 1,
The array of movable elements includes a first plurality of rows of movable elements extending along a first geometric dimension and electrically connected therebetween,
The electrode comprises an electrode array comprising a second plurality of columns of electrodes parallel to the array of movable elements and electrically connected between and not parallel to the rows of movable elements arranged along a second geometric dimension,
The controller generates a physical effect by changing the voltage difference between the jth column and the Ith row of the plurality of columns and generates the jth element of the Ith row of the plurality of rows to induce the movement of the I, jth movable element. And an apparatus operative to determine whether to indicate movement of the I, j-th element. 44. The method of claim 43,
And change the voltage difference by applying a voltage between the jth column and the Ith row of the second plurality of columns using a voltage source. 44. The method of claim 43,
And the voltage difference is changed by shorting between the jth column and the Ith row of the second plurality of columns. 44. The method of claim 43,
The row is perpendicular to the column. 21. The method of claim 20,
A voltage source is used to apply a voltage between the b th column and the a th row of the second plurality of columns, and after a predetermined time, disconnect at least one of the a th row and the b th column from the voltage source, and then continue to use the voltage source. By applying a voltage between the d-th column and the c-th row of the second plurality of columns, and disconnecting at least one of the c-th and dth columns from the voltage source after a predetermined time, thereby generating a physical effect and Instruct the movement of at least the a, b th movable element and the c, d th movable element to induce the movement of the motion. And wherein said controller is operative to determine whether to. 44. The method of claim 43,
And at least one of an I th row and a j th column is disconnected from the voltage source after the voltage is applied for a predetermined time. 49. The method of claim 48,
And the time ends while the I, j th movable element is still moving. 44. The method of claim 43,
And a position sensor for sensing the position of the I, j th element along the axis. 51. The method of claim 50,
And the position sensor comprises a capacitive sensor. 52. The method of claim 51,
After the voltage is applied for a predetermined time, at least one of the I-th row and the j-th column is disconnected from the voltage source, the time ended while the I, j-th movable element is still moving,
And the capacitive sensor measures a change over time in the voltage difference between the I, j th movable element and the I, j th electrode. 51. The method of claim 50,
And adjust the voltage of the voltage source using the position information provided by the position sensor. 51. The method of claim 50,
And adjusting the duration of time using location information provided by the location sensor. 51. The method of claim 50,
If the position sensor detects that the movable element has an abnormal movement pattern, the controller marks the movable element as a defect and the movable element is no longer used. 51. The method of claim 50,
If the position sensor detects a difference between movement patterns of different movable elements, the position sensor infers a difference in at least one operating characteristic of the movable element to take into account the difference in the operating characteristic when selecting a movable element. The method of claim 38,
And the mechanical limiter comprises at least one protruding dimple on at least one of the main face of the movable element and the main face of the electrode. Main = plane perpendicular to the axis. 44. The method of claim 43,
A voltage source is used to apply a voltage between the bth column and the a and cth rows of the second plurality of columns, and after a predetermined time at least one of (i) both the a and cth rows and (ii) the bth column. By disconnecting from the voltage source, the controller operative to determine whether to instruct the movement of at least the a, b th and c, b th movable elements to produce a physical effect and induce movement of the movable element. 44. The method of claim 43,
A voltage source is used to apply a voltage between each of the b and d columns of the second plurality of columns and a row, and after a predetermined time (i) both the b and d columns and (ii) the a row By disconnecting at least one of the voltage sources from the voltage source, the controller operates to determine whether the at least a, bth movable element and the a, dth movable element are instructed to produce a physical effect and induce movement of the movable element. Device. The method of claim 1,
The physical effect comprises sound and the property comprises at least one of amplitude and frequency. A method of manufacturing an electrostatic parallel plate actuator device for producing a physical effect that conforms to at least one characteristic of a digital input signal in which at least one attribute is periodically sampled, the method comprising:
Providing at least one electrostatic parallel plate actuator device and a controller,
Each actuator device includes an array of conductive movable elements defining a first side and at least one flat plate electrode defining a second side generally parallel to the first side, each movable element having a respective agent acting thereon. 1 is restricted to move back and forth alternately along each axis in response to an electrostatic force, wherein each movable element has a stop position and is driven away from the stop position only by the first electrostatic force, wherein the plate electrode is in the array of movable elements Selectively generate the first electrostatic force by operating to apply controlled time differences of potential differences with at least one individual movable element,
A controller is operable to receive the digital input signal and thus control at least one of the at least one electrode and the respective movable element and apply a potential difference in the sequence such that the physical effect exhibits the signal. Method of manufacturing the device. 62. The method of claim 61,
Providing the at least one electrostatic parallel plate actuator device is made using a MEMS process.

Images